Mechanical writing device



FIG. 1 is a top plan view of a mechanical writing device showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left end elevational view thereof;

FIG. 4 is a right end elevational view thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a mechanical writing device, as shown and described. 